A Long Island teacher is under arrest, accused of having sex with a female student multiple times over a three-year span.

Authorities say 33-year-old Daniel McMenamin, of Valley Stream, engaged in numerous acts of sexual conduct with a juvenile female victim beginning in November of 2014 when the girl was 14.

The alleged acts occurred through July of 2017, while McMenamin was employed as a math teacher at the Lawrence Woodmere Academy.

The victim was a student at the school during the course of the acts.

McMenamin is no longer employed by the school, but the circumstances of his departure are unclear. His attorney claims he left of his own accord in 2016 and was not fired. He has been working as a leave replacement teacher in a local public school district.

He is charged with three counts of second-degree rape, three counts of second-degree criminal sexual act, 24 counts of third-degree rape, 24 counts of third-degree criminal sexual act, and endangering the welfare of a child.

His attorney, William Jaye, denies the allegations and says the alleged incidents never happened.

"I can tell you there are many reasons why we have these types of allegations, and he proclaims his innocence that this did not happen," he said.

McMenamin pleaded not guilty and was ordered held on $280,000 bail.

"I stand by my son," his mother said as she left court.

Officials from Lawrence Woodmere Academy say they are cooperating with the investigation.

Students there were surprised at the allegations.

"I think it's kind of weird, because I wouldn't imagine him doing that to someone," student Ciara Leatherbury said. "He was a very nice person."